2. Spread the eggplant in a single layer on 2 baking sheets. Sprinkle lightly on both sides with salt. Set aside for 30 minutes. Wipe off the salt and pat dry with paper towels. Discard the paper towels.

7. In the baking dish, spread half the eggplant and top with half the onions. Add spoonfuls of the ricotta mixture, using half of it, and top with half the tomatoes. Repeat the layers with the remaining eggplant, onions, ricotta, and tomatoes. Drizzle the top with olive oil.

8. Bake for 1 hour and 10 minutes. Rest for about 30 minutes before serving. Cut into 12 squares. Reserve 4 squares for the linguine. Serve 2 squares per person.